Enclosures for refrigerated areas



y 1959 G. E. KLOOTE ETAL 2,896,271

ENCLOSURES FOR REFRIGERATED AREAS Filed Jan. 31, 1955 s Sheets-Sheet 1FIG. I \o 9 1. \fi2um2.:,, u 8

rrr U I 6 F 22 a? A 'II/ J 8 90 2 20 9G 8 I INVENTOJQS Joseph A.Pozcbelz I Gear 0 EK/ooze 6601;? 0/1/6181 FIG. 5 BY 4 4770 E) y 1959 G.E. KLOOTE ETAL 2,896,271

ENCLOSURES FOR REFRIGERATED AREAS Filed Jan. 31, 1955 3 Sheets-Sheet 2 744 H s l6 7 FIG. 5 9w 24L 9 66 I F1611 20 5/7 VII/2m 2 INVENTORS se h14. Pom/18,,

George E K/ooze e 0 M91291" July 28, 1959 G. E. KLOOTE ETAL 2,896,271

ENCLOSURES FOR REFRIGERATED AREAS Filed Jan. 31, 1955 3 Sheets-Sheet 3LLIJIIWIIIIIIIWIIIIII 7 l/VVE/VTOBS Joseph ,4. pole/2612 George E KloozeGeorge 0. M91251 2,896,271 I ENCLOSURES For: REFRIGERATED AREIAS w e-Kbde nd m e 1- M r c nteen and'Joseph A. PotchemMarne, Mich, assignors,by mes'ne"assig nrnent s, 'to Haskelite Manufacturing Gorporation, acorporation of Delaware Application raaaary" 31, 1955, serial No.484,948

1113mm; (CH4 20 -4 This invention relates to the construction'ofenclosures particularly adapted but not necessarily limited torefrigerated areas and more particularly to such an 'enclosureconstructed of synthetic resin materials.

The use of synthetic resin materials 'for the construe tion ofenclosures for refrigerated areas has many struc-' tural and functionaladvantages. a

In the construction of walls and other enclosing members forrefrigerated areas, moisture constitutes one of the majorunsolvedproblems of the industry. Moisture, even when present in onlyslight quantities, will migrate toward and collectin a zone of lowertemperature. Prior to this invention, all usable thermal insulatingmaterials have been porous to the migration of moisture. Attempts havebeen made to seal these materials in moisture tight jackets. Theseattempts have met with only partial suc cess since the slightest failureof the sealing jacket per'-" mitted entry of moisture. Within arelatively short time a substantial accumulation of moisture resulted.Once this occurs, the only known solution'is replacement of 3 theinsulation. By means of this invention, enclosures for refrigeratedareas may now be built with a laminated material having a moistureimpervious face'and a moisture impervious thermal insulatingcorematerial. Thus, even though the" fa'cingmaterial isaccidentallybreached, there Will be no; opportunity for the moisture'toenter and collect; Thus," the material will'maintain its thermale'flieieney' through out its life rather than rapidly losing it due totheac'cum'ulationo'f moisture. Thus, this invention solves ne'flor themost serious problems in'the fieldof enclosuresfor' refrigerated' areas.It also, for the first time, provide's'a practical and economicallyfeasible, moisture'proof'thermalinsu'lating material for other types ofstructures;

This invention has the further advantage of providing a durablematerial. It is durable since it cannot collect. moisture and,therefore, retains its thermal efii'ciency indefinitely. It is durablebecause it is resistant to corro-' sion, rot and fungus attack. Itrequires no painting or. other external finish either to preserve itsphysical 'conditionor appearance. 7 V I It is a material that is lessexpensive than theretofore known materials serving the same' purposes.The core material has a low coetficient of thermal transmission and,therefore, serves as one of the most eflfective'thermal insu latorsknown. The panels are light Weight and according- 1y easily handled.They are adapted to rapid andeasy installation, thus materially reducingthe initial costof the structure. The panels are highly resistant toshock loading and will endure rougher treatment than hereto fore knownmaterials usable for the same purpose.

The material is easily cleaned since it provides a nonabsorbent, smooth,interior surface. This surface may be quickly and easily cleaned bysimple washing methods.

Where the refrigerated area is designed for use inconnection'withfoods,'thismaterial is particularly desirable 70 because it can bedesigned to be odorless," tasteless and inert in the presence offoodstutfs. Itcan also be de- 2 signed to be proof againstaaaeab any oftheacidsor other "chemicals coiiiniimIy pr'eser it 'in connection withfoods irrespective of whether they are 'fru itsfvegetables or meats.

These and other advanta erof taunt/ema l; a; readily understood by thoseacquainted with thelco'nstruc Fig. 4 is "an" enlarged, "fragmentary,sectional view or the j'oin't "betwee'n'the stationary wall and the doorof an enclosure embodyihg'this invntion.

FigfS is 'an enlarged, fragmentary, sectional view of. thisinvehtionapplied to'a structure for a refrigerated arealrav'ingarigidfmetallic,-exterior shell. Fig; 6 is a sectional, elevational view of aportioniof astructure "'inlwhieh'thisinvention is applied to an'exis't ing shellstructure where the"interior surface of the she-'11 is uneven;

Fig. 7 is areal-aged, fraginentari", e'etioiialliie v'rfofl a clipused'to mount the panels inthe enclosure'shown inFigTG.

Fig. 8 is anfeaia'r'ged, fra mentar secuoaafiievfor invention V v I Fig;9 is; "an enlarged,fragmentary, sectional view of typical wallt'o'ceilin'g joint in'ahenclosure embodying this still another method'of 'aaashrngth enclosure, panels of' this" invention to a supportingshell structure Fig. 10 a a fragmentary, sectional view ar modified;

construction for the'joint between the panels of this in ventio'fi'. My

Figill'is a fragmentary sectional new illustrating a means that "thcircumstances, they may" not exhibitsligli't hygro'scopicalcharacteristics? This" invention' 'maybe exaautea; in a 1111351153. offerent waysIfQSeVe'r'al of thes'e'ways "are 'describedin thef:followingpara'graphs. These; howevenl are not to be; considered asmutually exclusive of allthe various ways in which thisinvention"carfbefcflried out.

Primarily"th is inventioii c'ontempiates' the construction of anenclosure for a refrigerated area from laminated panels ofsyntheticfresin"material or the type. disclosed in ounc -pendinapplication Y entitled Method of Making Lam'ihated"lfanelsfserial No.419,498, filed; January .13, 195 5, nov'vjabandon'ed This inventioncontemplates'the constructioifof s'uc'h enclosuresfrom these panelseither as a self supportingfentir'ely self suff cient structure or. the'use ofthes'e'panelsas a ming material for existing shell""struc tures,With the shells serving as a protective structural: housiiig 'forfthepanels.

Tr f of substantl' theti resin "which vention lhe "terms moisture"impervious" andffnon liygroscopic are used to describe certainproperties L 'of 't'he lsyiith e'tic resins em: I ployed. 'It'i's to beunders'tood thatfthese terms as. 1

terials are charaeteri'z'edlby these prop erties forall practical"purposes but" not thatithejy are. absolutely impervious to "moisture orthatfunder proper nip-em v'es are fabricated basicallyof a core ffl p fin i y, pa ded; eellli aterial' having] a low coefficient lot-j .TQ l ore1176 b nd e" on or both "faces," a dens ty facing fs'heet of syn-.1. a,I a v oisture 'impervious' and nonhy-f. grosc'opic'. The'se' faciii'g'sheetsare designed to have high A impact strength and for this purposeare normally reinforced with a fibrous material such as filamentaryglass. The facing sheets are designed to support a substantial portionofthe loading appliedto the panel. The core material serves the dualpurpose of acting as the web of a beam and as the thermal insulatingmedium of the panel. It is essential that the core material or at leastthe major portion of it be non-hygroscopic and impervious to moisture.

Referring to the drawings and specifically to Fig. 1, the numeral 1indicates an enclosure having side walls 2 and 3, a front wall 4, aceiling 5 anda floor 6. Each of these components is made up of panels 7.

Referring to Fig. 2, the panels 7 each consist of a core 8 of a lowdensity, rigid, expanded cellular, resin material. Each cell of the core8 is an entirely self-contained area,'hermetically sealed from eachadjacent cell. This is necessary to provide a material having a lowcoefficient of thermal transmission and one characterized by itsimperviousness to the passage of moisture. 7

Although various materials may be used for this purpose, one of the mostdesirable materials from the standpoint of thermal efficiency, lightweight, low cost and imperviousness to moisture is rigid, expandedpolystyrene. It is preferable to select an expanded polystyrene having adensity which will give the panel good structural characteristics. Ithas been found that expanded polystyrene having a specific gravity inthe range of .032 to .072 provides a desirable core material for generalapplication in this invention. This material has a K-factor of about0.24. Throughout this density range the K-factor remains relativelyconstant. Density ranges both above and be low the range given have asomewhat higher K-factor and are, therefore, somewhat less desirablefrom the standpoint of thermal insulation. In the case of high surfaceloadings, such as are experienced in floor panels, the denser expandedpolystyrene core material is used.

The facing sheets 9 of the panel may be of any one of a number ofdifferent materials. A preferred materiai, from the standpoint ofdurability and cost, is a high density, polyester resin such as Hetron92, sold by Hooker Electrochemical Go, into which there is embededfilamentary glass either in random or woven form as a structuralreinforcement. The thickness of this sheet may vary depending upon theparticular requirements of the structure for which it is to be used.This thickness may vary from 0.015 to 0.060 of an inch but normally itis approximately 0.018 to 0.032 of an inch.

Where the structure is of the type illustrated in Fig. l, in which thereis no outer, protective shell, it is neces sary that the core 8 beenclosed on both surfaces by facing sheets 9. Where, however, the panelsare used as a lining material and thus their external faces areprotected by. the shell structure to which they are attached, asillustrated in Fig. 6, the external facing sheet may in some cases beomitted.

The facing sheets 9 are bonded to the core 8 by a sultable syntheticresin which is non-hygroscopic and impervious to the passage ofmoisture. It also must be a resin which will not act as a solvent, inits unpolymerized condition, for the material of the core 8. Where thecore material 8 is polystyrene and the facing sheets are a polyesterresin, an epoxy resin such as BR-18795, sold by Bakelite Co., has beenfound a suitable adhesive.

A plurality of panels 7 may be assembled into a unitary structuresuitable for use as a wall, ceiling or floor section of an enclosure bybutting the ends of the panels together as shown in Figs. 2, 5 and 9, byusing a lap olnt as shown in Figures 3 and 11 or by employing a tongueand groovelapping joint as shown in Figure 10. As may be seen in Fig. 2,the panels 7 making up the floor, ceiling and walls of the enclosure 1are butted at their edges and the resulting joint (Fig. 2) sealed bymeans of a suitable adhesive such as an epoxy resin or an epoxy resinmodified by loading with a suitable 4 inorganic material to increase itsviscosity at the time of application. The resin in the joint 10 servesthe dual purpose of providing a moisture tight seal and of firmlysecuring the panels together in a rigid, structural unit.

In many cases it may be desirable to cover the joint with a battingstrip 11 to assure a complete moisture seal at the joint in the eventthere are any breaches in the bonding adhesive used at the joint. Thebatting strip 11 also protects the joint against mechanical injury. Thebatting strip 11 is normally of the same material as the facing sheetsand is bonded to the facing sheets by the same adhesive used to form thejoint 10. Where the backs of the panels are accessible, a second battingstrip 16 is frequently applied to the joint at the back surface.

Where the panel 7 of the ceiling 5 and a wall 2 abut, the resultingjoint 12 (Fig. 8) is formed in the same manner as the joint 10 with thepanels bonded together by means of a suitable adhesive. Again, ifdesired, the joint may be sealed and protected by means of a battingstrip 13. In this case the batting strip 13 is identical to the battingstrip 11 except that it is L-shaped in crosssection. It is secured tothe panels 7 by the same type of adhesive used for the batting strip 11.If greater strength is required in the joint, the pocket 14 formedbetween the batting strip and the apex of the joint may be filled withthis adhesive at the time the batting strip is installed. Again, wherethe back faces of the panels are accessible, a second batting strip 17,similar in structure to the batting strip 13, may be applied.

A typical floor installation is illustrated in Fig. 3 where the floorpanels 6 are shown as supported at suitable intervals by structuralmembers such as the I-beams 20. The spacing between the I-beams willvary from one installation to another depending upon the nature andseverity of the expected loading.

For the purpose of providing a smooth floor, the edges of the floorpanels are designed to provide a lapped joint. The use of the lappedjoints makes it unnecessary to apply a batting strip either to protectthe edges of the panels at the joint or to assure a moisture tight seal.In his construction, each of the panels has an outwardly projecting laptongue 21 having a thickness equal to substantially one-half that of thepanel. The edges of the facing sheets 9a of the panels extend beyond themargins of the panels and are folded. The folded edges are bonded to theedge of the panels to provide a protective flange 22. When the panelsare brought together, the protective flanges 22 abut. Since they providea smooth, radiused band 23 at the surface of the panel, there is notendency for objects moving over the panels surface to dig into thejoint, get beneath the facing sheets and tear them loose from the corematerial.

It is characteristic of many foamed synthetic resins and particularly ofexpanded polystyrene that they exhibit relatively low strength intension and relatively high strength in shear. It is, therefore,desirable, wherever possible, to cause loads to act in shear rather thantension. The folding over of flanges 22 causes any loadings tending topull the facing sheets 9a from the core 8 to act in shear along themargins of the panels rather than to act in tension at the surface jointbetween the core and facing sheet.

The small pocket formed between the radii 23 is preferably filled withthe bonding resin used to form the joint. This assures a tight moistureseal and provides a smooth continuity of surface, further eliminatingthe possibility of damage. The panels are locked together by this sameadhesive which is applied to all abutting surfaces 25 of the joint.Where pockets 66 may be formed within the joint, these preferably arefilled with adhesive. The resulting joint is both strong and moisturetight.

While this type of joint has been illustrated as particularly desirablefor the construction of the floor, it will be; r ecognized that it maybe .usedon the walls and ceiling, eliminatingthe necessity for-the'batting strips 'll.

The resulting surface is smoother and,--therefore', moreeasily cleaned.

Where the floor panels 6 are to be subjected to substantially higherthan normalloadings; theymay be reinforced by making the core thickerand by-using a core material of substantially higher-densityadjacentthetop surface. Such higher density core materials include foamedisocyanate resin or slabs of a high density ex panded polystyrene,laminated to slabs of a low density polystyrene. If necessary, a woodenlaminate 9b, Fig. 11, may be inserted between the facing sheets 9a andthe thermal insulating, low density core 8 to give the panel greatresistance -to crushingloads such as that ever, is not considered tooserious in this constructioninasmuch as the'wood panels are'notreliedupon for thermal insulation. The moisture,'irrespective of the degreeof-concentration, will not enter the non-hygroscopic, water imperviouscore material 8 to lower its thermal insulating efficiency.

The door 25-for the enclosure is made from the same laminated,-syntheticresin panels. Since thesepanels may be readily sawed and drilled, theenclosure may be erected and the opening for the door cut out afterward.Where such a cut-out is made,the exposed edge surfaces of the corematerial 8 are enclosed and protected by covering them with-a somewhatU-shaped channel section of filamentary reinforced, syntheticresinof thesame type as that used for'the facing sheets 9 and for the battingstrips 11. This channel may be considered as the protective edge jacket26 (Fig. 4). The jacket 26 is applied by bonding it to the edge of thepanel, using the same type of adhesive employed for attachment of thebatting strips 11. The application of the jacket 26 restores pro"tection to the edge of the panel against mechanical injury. It will berecognized that all these operations can be executed easily at the siteof installation.-

The jacket also serves to reinforce thepanel for theinstallation ofhardware-such as the latch keeper 27. 'To' provide means for attachmentof fasteners and'to furtherreinforce this area, a U-shapedelip' 56 ismounted-to the panel. -This c1ip and its application forthis purpose isfully described in-our copending application entitled Method andMeansfonSecuring Fasteners to Low Density'Core Panels, Serial No. 485,228,filed January 31, 1955.

The 'clip 56 is of a high-density, syntheticresin having" a filamentaryglass reinforcement. It is similar in ma-- terial to the jacket 26.

To mount the clip 56, s lot s are routed in the panel 7 through thejacket 26, facing sheet -9 and partially through the core 8. Either thelegs 57 -of the clip are coated with adhesive or the slots are partiallyfilledwitliadhesive and the clip then pressed intothe slotsi The latchkeeper '27 is installed by means of 'screws' threaded into the clip-56,jacket 26 and-facing sheet' 9. t This combination provides sufiicientthickness for the screws threads to obtaina firm anchorage to thepanel.

The legs. 57 of the clip serve to transmit the loads imposed by thelatch-keeper27 tothe core as shear loads rather than tension' loadsrTension loads -havea tendency to separate'the facing sheet 9-frorrrthe-'co're'8.

Since expanded; cellular,--synthetic resin-mater'ials arecharacterizedbyhigh shearstrength, the clip 56 provides a durable and substantialsupport for the-latch keeper which will not be subject to failure undertheheavy loads imposed by the operation of the latch.

The slab detached from the wall proper in the formation of the doorwaymay be used as the door-25; The

6 edged the -door is covered by a protective jacket 26.

To provide a suitable reinforcement for mounting the latch mechanism '28including the handle 29, U-shaped clips 56and 56a are mounted on thedoor. The mount ing of the clips 56 to the door is identical to that ofmounting them to panel 4. To avoid making aligned cutsin the panel" fromboth faces, the clip 56a, on the interior "face of -the door; is turnedwithrespect to the clip 56 on: the exterior face. The shank or stem ofthe handle 29 is seated in a suitable opening through the door. It isdesirable to prevent airleakage about the handle by providing suitableresilient gaskets about the shank adjacent each face of the door.

Although in some cases it may be desirable to provide internalreinforcement of the panelin the areas of the hardware, in the normalinstallation this is not considered necessary.

The gap between'the door 25 and the edgeof the Wall panels 4 may besealed in any suitable manner such as by the use of the compressiblegaskets 39.

The'construction of the joints 30 (Fig: 10) provides a self-closing,interlocking union between the panels. In this construction, the paneledges in addition to being lapped are provided along their outer marginswith a tongue 31 and a groove 32. The contacting edge 33 of the tongues31 are inclined to urge the panels together as they are pressed flush toeach other. The

grooves or channels 32 are designed to be slightly deeper than thetongues 31 whereby the panels may be brought into tightabuttingrelationship before contact between the ends of the tongues andthe bottoms of the grooves prevents further alignment of the panels. Thejoint 30 is secured and sealed by the application of an adhesivesuch asthe adhesive used to attachthe battingstrip 11,

on all contacting surfaces of the edges of the panels. Thissimultaneously seals the joint against the passage of moisture andfirmly secures the panels together as a structural unit.

In the construction of the joint 30, the panel facing' sheets 9preferably extend beyond the edges of the panels and are turned in toform edge flanges 34. The small pocket formed at the surface of thepanel by the radius ing of the facing sheets at the panels edge ispreferably filled with a bead 35 of adhesive. This assures a smooth ointand a positive moisture seal. The joint illustrated a tortuous pathbetween the panels'which may be more readily sealed against moisture.

A number of means may be used for securing the panels to the structureof an external shell where such exists. A few of these are illustratedin Figsr5, 6, 7 and 9;

The means of-attachment illustrated in-Fig. 5 is de-" signed for thesituation where the shell structure includes channel section studs fit)covered by an external skin 41 of suitable material such as aluminum'orstain-' less steel. In this situation it is assumed that the externalfacing 41 is applied after the insulating panels 7 have been erected andattached to the'studs 46. For

the purpose of effecting this type of erection, angle strips 42 of thesame material as the batting strips 11 are secured to the studs 40 bysuitable means such as rivets 4-3. The panels 7 are-then secured to theangle strips 42 by'a suitable adhesive such asthat used to attach thebatting strips 11. The panels '7 are held in position by temporary propsuntil the adhesive has set. When the adhesive has set, the panels arefirmly secured to the studs 4-0. Prefera ly, the panels areso sized thattheir joints will fall at the studs 40. These joints'may be of any ofthe various types described with the actual joint 44 formed and sealedby the same adhesive. used to attach the angle strips 42 to the panels.Where the joint is of the simple type illustrated, it is normallycoveredand protected by a batting strip 11, also adhesively secured tothe facing sheets of the panels.

After the panels 7 have been secured to the studs 40, the surface sheets41 of the shell are erected and secured to the studs 45) by blind rivets45. Such an arrangement provides a good structure because the surfacingsheets 41 and the studs 40 provide a firm and positive protectivestructure for the enclosure while the panels 7 provide complete thermalinsulation for the enclosure. The entrapment of moisture in the spacebetween the panels 7 and the surfacing sheets 41 is immaterial in thistype of construction so far as the insulating material is concernedsince it is impervious to moisture. Where the back surface of theinsulating material is protected against mechanical injury such as theprotection provided by the surfacing sheets 41, the facing sheet 9 onthe back face of the insulating panels 7 may be omitted.

Fig'. 9 illustrates another method of joinder of the panels to thestructure of a surrounding shell. This method also assumes that the backof the insulating panels will be accessible for erection of the panels7. In the particular illustrated embodiment of this method, the panelsare secured to an I-beam 48. For the purpose of making the attachment,the panels 7 on the back face are provided with a cutout 49 ofsuflicient depth to seat the flange of the I-beam 48 flush with the backsurface of the panels. Anchor strips 50, similar to the batting strips11, are secured to the I-beam on each side of the web by means of rivets41. A substantial portion of each of the anchor strips 50 extends beyondthe I-beam and is secured to the surface of the panel by a suitableadhesive. As soon as this adhesive has set, the panels will be firmlyheld to the I-beam 48. After this has been accomplished, the I-beams areenclosed by attachment of exterior facing sheets.

The fact that the facing sheet 9 of the back face of the panels 7 isbreached for the purpose of making this attachment is not important whenthe core material used in the panels 7 is non-hygroscopic and imperviousto moisture. The breaching of the moisture impervious facing sheets willnot permit moisture to enter the core 8 to impair or destroy the thermalefficiency of the panel.

Figs. 6 and 7 illustrate another method of attaching the panels to asurrounding shell enclosure. This particular means of construction isparticularly adapted for use where the back of the panel isinaccessible, requiring blind attachment. This form of attachment isparticularly suited to situations in which the shell is masonry and tothose situations in which the interior surface of the shell is irregularso that the panels as a whole have to be spaced outwardly from the shellsurface sufficiently to permit them to clear all irregularities of theshells interior surface.

While this form of attachment is particularly suitable for masonrywalls, it will be recognized that it may be used with wooden and othertypes of non-masonry structures. While particularly suited to situationsinvolving inaccessibility of the panel backs, it is equally useful underpractically all other circumstances where the panels are to be attachedto a supporting structure. It is contemplated that this form ofattachment will be extensively used under all of these variouscircumstances.

This particular form of attachment is preferred over those illustratedin Figs. and 9 because it takes advantage of the fact that low densitycore materials such as expanded polystyrene have high shear strength.The legs of the clips transmit loads to the panel as shear loads ratherthan as tension loads tending to separate the facing sheet from thecore.

For the purpose of making this type of installation, the clip 5f; isutilized. Although the clip 50 may be of many different types ofconstruction, one particularly useful embodiment consists of anelongated U-shaped corrugated clip. The free ends of thesides of theclip are sharpened at 51 to provide a cutting and penetrating edge. Thisparticular clip is illustrated and claimed in our co-pending applicationentitled Clip for Mounting Panels, Serial No. 484,954, filed January 31,1955.

The enclosure to be lined with the panels 7 is prepared by firstattaching the clips securely to the shell of the enclosure. Where theshell is of wood or other readily penetrable material as suggested inFig. 7, the clip is secured by means of screws 52. Where, however, theenclosing shell is of masonry, suitable attachment means such as a screwand masonry anchor combination or a percussion set stud is used.Whatever means are employed for attachment of the clip to the shell, itis essential that this attachment be firm and stable so that the clipswill be rigidly held to the shell. The quantity and spacing of the clips50 will be determined by that necessary to provide adequate support forthe panels 7. This will vary from one installation to another.

After the clips 50 have been installed, their sides are coated with anadhesive bondable upon curing to both the facing sheets and the core.For this purpose an epoxy resin is desirable where the facing sheets area polyester resin and the core material is expanded polystyrene. This isthe same type of adhesive utilized for mounting the batting strips 11.With the clips 50 freshly coated with the adhesive, the panel is placedin position and then its inner face pushed or struck with sufiicientforce to cause the sharpened edges 51 of the clip to penetrate partiallythrough the panel. Of course, if the panel has a facing sheet 9 on theback surface, the force required to do this is substantially greater.Some of the adhesive on the sides of the clip is carried into the panel,forming a bond, indicated by the numeral 53, between the clip and thepanel core. Some of the adhesive piles up at the point of entry of thesurfacing sheet 9, forming a strong bead or fillet 54 further securingthe clip to the panel.

The depth to which the clip 50 is caused to penetrate the panel 7depends upon the circumstances of the installation. Normally the clips50 are provided with sides or legs having a length appreciably in excessof the depth of penetration necessary to adequately hold the panel. Bythis arrangement, the panels may be pushed onto the clip only so far asnecessary to provide a firm anchorage. Thus, if the surface of the shellstructure is irregular, as is indicated by the irregular surface 55 ofthe side wall in Fig. 6, the panels may be caused to stand out from thegeneral surface of the wall sufliciently to clear all obstructionscreated by the irregularities.

The several panels 7 forming a single wall or ceiling may be erected bypartially inserting them on the clips 50. When all the panels have beenso placed, they may be aligned to provide a flush surface by forcing theinwardly projecting panels flush with the other panels. This must bedone with sufiicient rapidity that it will be accomplished before theadhesive on the clips starts to set.

Normally, the panels when erected as a wall by this method will holdtheir position without external support until the adhesive on the clipsis set. Where, however, the clips 50 are used to mount ceiling panels 7to form ceiling 5, such as illustrated in Fig. 6, the ceiling panelsmust be supported until the adhesive is set. Since the panels arecomparatively light weight, this presents no serious problem. Panels ofthis type in four by eight foot sizes are normally light enough for asingle man to easily lift and place on the ceiling.

This invention is equally applicable to both stationary and mobileenclosures. It is useful in the construction of refrigerated rooms,portable containers, box cars and trucks. Because of its good structuralqualities, it will withstand the loadings characteristic of theseapplications including vibration and jar incident to use in mobileenclosures.

In addition to enclosures for refrigerated areas, it may ease-271* beused for'standard building construction, replacing the entire roofand'wall structures." It provides in a single construction component astructural support, a weather resistantv and weather'tight exterior; adurable, injury resistant'surfaceon both the :inte'rior and exterior andan' insulating'factor superioratoirthat of conventionally usedmaterials; In such "construction vit may-be used asthe' solebuildingmaterial 'or it maybe applied as the enclosureipaneling for a skeletonframe: I

An enclosure forarefrigerated-area-' constructed according to this'invention'has the' advant'age of a durable Wall of high thermalinsulatingiefiiciency." This thermal insulatingpefliciency willbe-retainedthroughout the life ofthe'enclosure; It has notendency t"loseits thermal:

efliciency due to the accumulation of moisture such as characterizesthermal insulating materials heretofore employed; It is also highlyresistant to -m'echanical injury. If injured, it may be quickly andinexpensively repaired by use of a patch of the same type of material asthat used for" the batting'stri'psi Small breaches may befilled withthe'adhesivef Boththe'repa'ir strip and the adhesive formmoisturetightseals to prevent the formation of pockets'into which dirtor other materials characteristic of refrigerated "area's'mayaccumulate. Since the panels retain'theirth'erm'al efiicienc'ythroughout their life,-- the frequent" replacement'commonly required ofpr'eviously'known insulatingmaterials is eliminated. This in itselfeffects a substantial'saving'in cost and in down time of' the"refrigerated' enclosure necessitated by repairs.

While a preferred embodiment and several modifications of this inventionhave been described, it will be recognized that various othermodifications maybe employed Without departing fromthe' principle ofthis invention. Such modifications are to be considered as included inthe hereinafter appended clairns,"unless'these claims'bytheir languageexpressly state'otherwise.

We claim:'

1. An enclosure for a refrigerated areacomprising a plurality oflaminated panels having on at least the surfaces exposed to the interiorof said enclosure a moisture impervious facing of synthetic high densityresin, a core having a loW coefiicient of thermal conductivity, saidcore being a rigid expanded cellular synthetic resin, the cells of saidcore resin being independent and hermetically sealed from each other,and a moisture impervious adhesive bonding said facing to said core, theabutting surfaces of said panels being adhered with a moistureimpervious adhesive to thereby form a strong moisture impervious jointwhich presents a continuous smooth interior surface in said enclosure.

2. An enclosure for a refrigerated area comprising a plurality oflaminated panels having on at least the surfaces exposed to the interiorof said enclosure a moisture impervious facing of synthetic high densityresin, a filamentary reinforcement embedded in said resin, a core havinga low coefficient of thermal conductivity, said core being a rigidexpanded cellular synthetic resin, the cells of said core resin beingindependent and hermetically sealed from each other, and a moistureimpervious adhesive bonding said facing to said core, said panels beingjoined so as to form an enclosure presenting a continuous smoothinterior surface, each of the joints thereof being sealed with anadhesive that is moisture impervious.

3. An enclosure for a refrigerated area comprising laminated panelshaving on their surfaces exposed to the interior of said enclosure amoisture impervious facing of synthetic high density non-hygroscopic,moisture impervious resin, a core having a low coeflicient of thermalconductivity, said core being a non-hygroscopic, moisture impervious,rigid expanded cellular synthetic resin, the cells of said core resinbeing independent and hermetically sealed from each other; and amoisture impervious adhesive bonding said facing to said core, the

10 facing :on each of said panels =:havinga down-turned flange portionextending over and 'adhesively secured 'to' at "leasta portion of an end-surfaceof-said-core and a pluralityof said panels being abutted so. asto :place the said fianges thereof in-contact,said-panels=beingJadhesively joined' together tot formsaid=-=enclosure so that? said facingpriesents a substantially smoothsurface at said--- joints."

4.- In an enclosure for a refrigerated area ,the' com-'- binationcomprising a plnrality-.of-'panels and adhesive means joining saidpanels together as said enclosure, said adhesive means'sealingzthe-joints between' said-pauels against the migration ofmoisture therethrough, the -surface exposed'to the-interiorofsaid-enclosure of each of said panels being covered by :a moistureimpervious facing of a synthetic high' den'sity-resin having embedded"-therein a filamentary glass*reinforcementand presenting a smoothcontinuous interior surface,--a core having a low coefficient of thermalconductivity, said-core being: of'rigid expanded" cellular "synthetic:resin, the cellsof saidc'ore resin 'being independent and hermeticallysealed from each "other;'a moisture impervious adhesive bonding saidfacingtosaid core, and a laminateresistan't to crushing under-loadadjacent themppersurface of those of said panels'forming-the floorofsaid enclosure'.

5. In an enclosure for a refrigerated area, the combination'of 'claim "1wherein the surface of each of said panels emosed to the-interior ofsaid enclosure is covered by a moistureimpervious facing of-ja highdensity poly-'- ester resin havingembedded-therein a filamentary glassreinforcement,'and said core comprisesa slab of rigid expandedpolystyrene;

6.'In an enclosure for 'a 'refri-ger ated'area, thecombination"comprising a pluralityrof: panels and means joining said panelstogether as said enclosure, adhesive-- means" "sealing .Lthe jointsbetweem said panels against the migration"of moisture therethrough, thesurface -exposed to the interior of said -e'nclosure of each of said 1panels being covered by a moisture imperviousfacing of a highdensitypolyester *resinha'vingembedded therein: a filamentary'glassreinforcement; and a core comprising a slab of rigid expandedpolystyrene, a moisture imper vious adhesive bonding said facing to saidcore, the core slabs of those of said panels forming the floor of saidenclosure being of a rigid expanded polystyrene of a higher density thanthe core slabs of the others of said panels.

7. A lining for an enclosure for a refrigerated area having a rigidshell, said lining comprising a plurality of panels joined together soas to form an enclosure sealed at the joints between said panels by anadhesive capable of preventing the migration of moisture therethrough,,the surface exposed to the interior of said enclosure of each of saidpanels being free of protuberances and covered by a moisture imperviousfacing of a synthetic high density resin, a core having a lowcoefiicient of thermal conductivity, said core being of rigid expandedcellular synthetic resin, the cells of said core resin being independentand hermetically sealed from each other, a moisture impervious adhesivebonding said facing to said core, and anchor elements secured to saidshell and to said panels for holding said panels to said shell.

8. A lining for an enclosure having a rigid shell, said liningcomprising a plurality of panels and means joining said panels together,means sealing the joints between said panels against the migration ofmoisture therethrough, the surface exposed to the interior of saidenclosures of each of said panels being covered by a moisture imperviousfacing of a synthetic high density resin, a core having a lowcoeflicient of thermal conductivity, said core being of rigid expandedcellular synthetic resin, the cells of said core resin being independentand hermetically sealed from each other, a moisture impervious adhesivebonding said facing to said core, and anchor elements rigidly secured tosaid shell and adhesively bonded to the surface of said panels forholding said panels to said shell.

9. A lining for an enclosure for a refrigerated area having a rigidshell, said lining comprising a plurality of panels joined together soas to form an enclosure sealed at the joints between said panels by anadhesive capable of preventing the migration of moisture therethrough,the surface exposed to the interior of said enclosure of each of saidpanels being covered by a moisture impervious facing of a synthetic highdensity resin, a core having a low coefficient of thermal conductivity,said core being of rigid expanded cellular synthetic resin, the cells ofsaid core resin being independent and hermetically sealed from eachother, a moisture impervious adhesive bonding said facing to said core,anchor elements rigidly secured to said shell, a portion of each of saidanchor elements penetrating said panels, and an adhesive bonding saidpenetrating portion of the facing and core of said anchor elements tosaid panels.

10. In an enclosure for a refrigerated area, the combination comprisinga plurality of panels and means joining said panels together as saidenclosure, each of said panels having a hook shaped tongue projectingfrom two of its parallel edges, the free end of the tongue on one ofsaid edges extending oppositely to the free end of the tongue on theother of said edges, the face directed toward the panel of the free endof each of said tongues being inclined and converging with said paneltoward the base of said hook whereby said panels are adapted to beforced into tight edge to edge relationship as said panels are alignedwith each other, means sealing the joints between said panels againstthe migration of moisture therethrough, the surface exposed to theinterior of said enclosure of each of said panels being covered by amoisture impervious facing of a synthetic high density resin havingembedded therein a filamentary glass reinforcement, a core having a lowcoeflicient of thermal conductivity, said core being of rigid expandedcellular synthetic resin, the cells of said core resin being independentand hermetically sealed from each other, and a moisture imperviousadhesive bonding said facing to said core.

11. A method of forming a refrigerator enclosure which comprises thesteps of providing an outer shell, attaching a plurality of spacedpanel-securing means to the interior surface of said shell, providing aplurality of panels, each panel having an expanded cellular syntheticcore portion and a moisture impervious facing of a synthetic highdensity resin adhesively secured to one surface of said core, applying amoisture impervious adhesive to the edge surfaces of said core and tothe surfaces of said panel-securing means and forcing the said panelagainst said panel receiving means so that the said receiving means atleast partially penetrates the said core, and repeating the step offorcing additional panels against said panel receiving means until theinterior surface of said shell is covered.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES Scientific American, September 1945, pages and 156.

Article entitled Polyester Chair Takes the Prize," reprint from ModernPlastics, August 1950, two pages.

Article entitled Sizes for Glass Textiles for Reinforcing PolyesterPlastics, reprint from American Dyestufi Reporter August 18, 1952.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nos2,896,271 I July 28, 1959 George E. Kloote' et al It is hereby certifiedthat error appears in the printed specification of the above numberedpatent requiring correct-ion and that the said Letters Patent shouldread as corrected below.

Column l, line 56, for theretofore" read es heretofore column 2, line45, for "means" reed mean column 10, lines 6'7 and 68, for enclosures"read enclosure column 11, line- 18, strike out "the facing and core' of"and insert the same'before the Word "said", first occurrence, in line18, same column.

Signed and sealed this 19th day of April 1960.

(SEAL) Attest:

KARL HWAXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents

